What It Is

An elderly woman finds she can't seem to follow a cheesecake recipe she's been using for years. While driving her car, this woman sometimes forgets where she is going and has trouble finding her way home. More and more often, she is confused. This woman has Alzheimer's disease. She could be your grandmother, your mother, your sister, your friend -- or she could be you.

The most common cause of dementia, Alzheimer's disease affects 4.5 million Americans, more of them women than men. And as former President Reagan's death from complications of Alzheimer's reminds us, this fatal disease profoundly affects not only the person suffering from it, but his or her caregivers, family members, and friends.

First discovered in 1906 by German physician Alois Alzheimer, Alzheimer's is a complex disease that is not yet fully understood. It starts in one part of the brain and gradually spreads to other regions, leaving behind abnormal clumps (plaques) and twisted fibers of protein. As it progresses, it causes confused thought patterns. Over time, Alzheimer's disease slowly robs a person of her language and reasoning skills, her memory, and ultimately her personality.

The odds of the getting Alzheimer's increase as a person gets older; as many as 10 percent of people over age 65, and close to 50 percent of people over 85 have the disease. A rare form of AD develops as early as age 40. But Alzheimer's is not an inevitable part of aging. The dementia associated with Alzheimer's is not the mild forgetfulness that many older people joke about.